An electromagnetic switchgear unit is described in German Patent No. DE 43 18 196 A1. By means of this electromagnetic switchgear unit, load currents are connected and excessive currents, mainly short-circuit currents, are limited. In this case, the first electromagnetic drive appliance is operated as an auxiliary system which, in the case of excessive currents, exerts a force on the movable contact element and, by this means, opens the contacts. This therefore prevents the contacts being in an undefined floating condition, in which the contacts could become welded, due to electrodynamic forces. Such weld-free contactors are employed in association with a circuit-breaker. For economic reasons, the contactor is usually provided with a circuit-breaking capability which is lower than that of the circuit-breaker. Its current limitation only acts to support the circuit-breaker. It is therefore necessary for the auxiliary magnet system of the contactor to respond at a higher current than that of the circuit-breaker. It is also a requirement that the contacts should, in the case of a short-circuit, be held closed by the main magnet system until they are separated from one another by the auxiliary magnet system of the contactor. In order to satisfy these two requirements, magnet systems are necessary which are larger than those for standard units with the same switching capacity.